David b



' 1 UNITED STATES PATENT FFICE.

DAVID R. IROGTOR, OF CHICAGO, ILLINOIS, ASSIGNOR TO HIMSELF AND JAMES F.MARSHALL, OF SAME PLACE.

SAW.

SPECIFICATION forming part of Letters Patent No. 361,238, dated April12, 1887.

Application filed May 25, 1886.

To aZZ whom it may concern.-

Be it known that I, DAVID R. PRooroR, re-

, siding at Chicago, in the county of Cook and idly, andwhich will notheat in use; and its nature consists in the improvements hereinafterdescribed and claimed as new.

In the drawings, a to indicate the face-plate of the arbor; b, thecap-plate; 0, screws; d, cutting-blades; e, grooving-blades; f,cuttingpoint; g, grooving-points, h, roughened parts on the saw-blades.

The arbor a b is made of cast or other suitable iron, and the base a isprovided with a hollow projection or collar, a, through which thearbor-shaft or mandrel passes and against which the ends of thesaw-blades are made to fit, as shown in Fig. 1. The cap-plate b fitssnugly over this collar, and is attached to the base by means of thescrews cfwhich pass through it and the saw-blades and into thebaseplate, so as to clamp and hold all of the parts firmly together.

The inner ends of the blades are concaved to fit against the collar aand beveled off at their edges,so as to fit snugly and firmly againsteach other, as shown in Fig. 1. These blades are arranged to standradially from the arbor, and the blades (1 are provided withcuttingedges,which are separated, so that either side may be easilysharpened, and are beveledat the inner sides, .as shown. Thesecuttingedges are easily formed and easily keptsharp, as they may besharpened by grinding or by filing, as may be most convenient.

The blades 6 have their outer ends provided with agrooving-tooth, g, assl1own,which tooth is flat or chisel-pointed,so as to groove out thematerial separated by the cutters. The cutters 7) project slightlybeyond the groo-vers g, as shown by the circular line in Fig. 1. Thecuttersf may have a slight set, if desired; but if Serial No. 203,260.(No model.)

the cutting-edges are notbeveled off or allowed to be worn down upon theoutside, setting will not be necessary.

The side surfaces of the bladese are roughened, as shown at h, by afile-cutter, which gives a smoothing-surface to such blades as'are soroughened. This feature is especially desirable in crosscutting seasonedlumber, as it gives the cut a smooth fine finish. For ripping orordinary sawing in seasoned lumber, they are also desirable forsmoothing thekerf; but for such sawing they may be omitted, as I do notlimit the other features of my improvement to their use in combinatiofiwith this roughing h.

The blades (1 e are consecutively numbered around the saw,and the arborcorrespondingly numbered, so that in case of breakage or injury thedamaged blade can be replaced, and also so that if for any purpose thesawis taken apart the blades can be properly replaced. The arbor is alsoproperly turned or finished, so that when the cutting-blades are appliedthey willform in a true plane without bending or shaping them.

In a saw formed in this manner the spaces between the blades oroperating parts form air-spaces, which have a fan effect, and keep thesaw cool-under all circumstances to which a saw. is properly subjected,and by this arrangement the saw is easily repaired in parts in case ofbreakage or accident, is easily kept in running order, and effective inits operation.

I have described my improved saw in what I consider its best form, butit is evident'that the saw-blades may be formed of a single plate, cutaway,as indicated by the dotted lines 43 in Fig. 1, or so that theblades (2 6 will be integral at their inner ends, and that when so madethey may be attached to the arbor in the usual manner. Thegrooving-teeth may also be made V-shaped, as shown at g in Fig. 3,instead of being square or chisel-pointed, which may be more desirablefor some purposes.

I do not claim, broadly, the application of a smoothing-surface to thesides of asaw-blade, as that is shown in Patent No. 118,800, on a jig orscroll saw. A roughened surface suited to such a saw would not beadapted to a circular saw which runs continuously in one direction andrequiring a clearing-space to free ICO the sawfrom the dust. ly makingthe smoollr vening spaces located between the outer ends ing edges orprojections continuous and inof said blades, substantially as described.elining their backward endsdownward, aconi- 2. The roughened smoothingsurface it, 15 plete smoothing-surface for a circular saw is 1 formed ofdownwardly and rearwardly inforn1ed,with spaces between the ridges forthe clined projections or smoothers, in combinadischarge of the dust.tion with the circular saw formed of separate That I claim as new, anddesire to secure radial blades, substantially as set forth. by LettersPatent, is r 1. A circular saw having its actingrim coln- DAVIDPROOI'OR' posed of radial cuttingblades d and radial Witnesses:grooving-blades a, alternating with and sup- 0. \V. BOND, porting eachother, and provided with inter- HARRY T. JONES.

